Potatoes and Chips on a Gluten Free Diet

Contrary to popular opinion, potatoes are not root vegetables but are in fact stem vegetables, otherwise known as starchy tubers. They are the swollen ends of the underground stems of the potato plant, which is an annual plant in the nightshade family. Potatoes are native to the South American Andes, where they have been cultivated for over 7000 years. Now though, they are everyday staples around the world, thanks to their high energy content, their wholesome taste and their culinary versatility.  

Gluten is the name given to a family of proteins found in certain cereal grains including wheat, rye and barley. As potatoes are not grains but tubers, they are naturally free from gluten. This means that potatoes in their basic form are fully safe for coeliacs. 

The problem comes when potatoes are exposed to cross-contamination with gluten-containing foods or combined with gluten-containing ingredients and seasonings during the cooking process. In these cases potatoes may not be fully gluten free. 

There are over 4000 different varieties of potato. Luckily, these varieties can be grouped into four main categories: starchy, waxy, all-purpose and sweet potatoes. 

Starchy potatoes 

Also known as floury potatoes, their centre turns fluffy when cooked, making them perfect for mashing, roasting, baking and making chips/fries. Common starchy varieties include: King Edward, Maris Piper and Russet. 

Waxy potatoes 

Waxy potatoes have smooth, firm flesh and retain their shape when cooked. They are great boiled, in stews and in salads. Common waxy varieties include: Charlotte, Fingerling, Jersey Royals and Maris Peer. 

All-purpose potatoes 

As the name suggests, these varieties of potato work well anywhere – they are somewhat fluffy but hold their shape well enough for most dishes. Common all-purpose varieties include: Desiree, Red Gold and Yukon Gold. 

Sweet potatoes 

Technically a different plant and food type to regular potatoes (they are classified as tuberous roots) sweet potatoes are generally grouped together with potatoes because of their similar nutritional profile and culinary functions. They can be used in all the same ways as starchy potatoes but have a slightly sweeter taste. 

Potatoes are remarkably versatile to cook with. For example, depending on the variety of potato, they can be roasted to make roast potatoes, boiled to make boiled potatoes, baked to make baked or jacket potatoes or fried to make chips or fries. If cut very thinly, after frying potatoes can also be dried and seasoned to make crisps or potato chips and tortilla chips. 

Chips or fries and crisps or potato chips (whatever you happen to call them) are all gluten free in their basic form. And if you prepare them yourself in fresh oil, there is no need to be concerned about any gluten presence. The problem comes when someone else has prepared them.  

Sometimes, to make chips or fries extra crispy, restaurants or manufacturers will coat them in wheat flour, which of course contains gluten and is a no-no for those with any kind of gluten intolerance. Crisps or potato chips, on the other hand, may be flavoured with gluten-containing ingredients. For example, salt and vinegar crisps are often flavoured with non-distilled malt vinegar, which comes from barley – a gluten-containing cereal grain. What is more, some crisp/potato chip brands may use gluten as a stabilising agent during the production process or as a carrier substance for flavourings too.  

In both cases, chips/fries and crisps/potato chips could also be subject to cross-contamination during frying. 

If potatoes are fried in oil that has been used to fry breaded or battered foods, such as onion rings, chicken nuggets, calamari or battered fish, then they are likely to pick up sufficient traces of gluten from the oil to cause a reaction for someone with coeliac disease. 

The same goes for boiling. If the water used to boil potatoes has previously been used to boil gluten-containing foods such as pasta, then that could cause cross-contamination of the potatoes, making them unsafe for those with coeliac disease.  

When shopping for pre-packaged chips, fries, crisps or potato chips, always carefully check the packaging and ingredients list to make sure the product you are buying is gluten free: it doesn’t have gluten-containing ingredients and has been prepared in an environment free from the risk of gluten contamination. If you are in any doubt as to a product’s gluten free status, or something on the label/packaging isn’t clear, it is always worth contacting the manufacturer to check. 

When buying chips or fries out, whether from a restaurant, chip shop or food stall, have a look at what else is sold there and ask the waiter or server what other foods are cooked in the same chip oil, if any. Unless the cooking staff can guarantee that they use a separate gluten free fryer for their chips/fries, we recommend against risking it.  

Even if you can’t be confident that the chips or fries on offer are gluten free, the great news is that they’re really easy to make yourself at home. Just peel and cut starchy potatoes into chip-sized pieces and deep fry or oven roast them. And of course, Schär’s got your back for other gluten free chip and potato meal ideas. Check out our recipes for gluten free fish and chips, gluten free potato croquettes and our take on the timeless classic, baked potatoes.